Before and Afters

I love the visual perspective on changing coasts, and can't resist posting this one. Back when I worked for Surfrider Foundation I put together this little photo monitoring project for the Elwha (see page 6 here, for example). As part of the program a few sites were established in the Elwha estuary for repeat photography. A few days ago I took McHenry and Theo for a walk down on the nice new bar down at the river mouth:

and took the opportunity to snap some photos from one of the sites that we photographed back in 2004-2006. Here is the result:

A view of the estuary shot in February of 2005

The same view shot in February 2014

An(other) update from Elwha

I recently had an opportunity to compile some thousands of individual photos taken from a site above the mouth of the Elwha River into a single timelapse - this collapses over a year of observations into two minutes. It is hard to watch - this is raw with all photos taken at night, during bad weather and during all phases of the tide, included. Despite that, though, it provides a nice view of the changes that have taken place at the river mouth over the past year. A WWU student is currently working on a cleaned up version of this perspective, which should be available in a few months.

Interesting patterns on the beach after the last survey a few days back. Notably, the most interesting changes are happening on the beach to the WEST of the river mouth (Line 132 above), which continues to accrete due to the transport of sand on to the beach face. The sand is also moving higher on to the beach there, and now reaches up to over 4 m above MLLW:

Grain Size photo from 12 February 2014 at 4.25 m elevation at Line 132.

even just a few months ago that elevation looked like this:

Grain size photo from 15 December 2013 at 4.25 m elevation at Line 132.

To the east of the river mouth at Line 164 the areas that I can access are no longer really beach - the river channel now cuts across that site such that I can no longer reach the outermost bars. You can see the profile truncated in the profile from 12 February - that is a river channel. You can also sort of make out the migration of the river channel back to the east that happened in December in the timelapse above, though you sort of have to look hard.

Finally, on the eastern part of the floodplain not much appears to be happening on the beach. There appears to be some sand moving around (there are pockets of it everywhere, especially down low on the terrace at a variety of locations), but not enough of it has moved high enough on to the beach face to really start inflating those profiles (though it does appear that erosion has slowed down at both Line 190 and 204. We are POSSIBLY seeing some finer grain size material moving in on the beach at Line 190:

Grain Size photo taken at 1.50 m elevation on the beach at Line 190 on 12 February 2014.

Though its worth noting that the main channel of the river now appears to be position just to the east of this site (approximately between Line 164 and 190) and is pointing east in the alongshore direction. In fact, there are new exposures of the former coarse low tide terrace in places that had been covered with new sediment for the past months, probably because river flow has excavated this new material and moved it further alongshore. The river itself may be transporting some of this sand up on to the beach. Additionally, this beach has seen pulses of fine material before, especially this time of year:

Grain size photo taken at 1.50 m elevation on the beach at Line 190 on 5 February 2013

Grain size photo taken at 1.50 m elevation on the beach at Line 190 on 14 February 2012

Restoration in fast forward

One of the more dramatic and large dedicated beach restorations is happening right now at Seahurst Park in Burien:

View Larger Map

Projects like these - in which an attempt is being made to more or less re-assemble the historic morphology of the shoreline, are a relatively new thing. They take quite a bit of effort - its a full-on earth moving process:

But the cost is likely worth it - the expectation is that these sorts of projects provide all sorts of benefit. I am particularly interested in how these sorts of projects work in terms of the beach's role as a barrier against the sea. As a result, I was able to work together with Steve Roemer at the City of Burien and Joe Weiss at the Puget Sound Skills Center to get a time lapse camera up on the north side of the project looking south. Some of the first photos came in over the holiday and are here:

There will be more to come on this one...

Glines Canyon Dam now invisible

In case you didn't notice the latest happenings on the Elwha River - the Glines Canyon Dam, while still a bit there, is now invisible. A blast a few days back (see John Gussman's footage of the blast here) took out the last remaining section of the dam visible to the web cam.

Before: Glines Canyon Dam Site on 26 January 2014

After: Glines Canyon Dam Site on 27 January 2014

The blast also lowered the river at the dam site, increasing the gradient of the river, and thereby increasing its erosive capacity. As a result there was an almost immediate uptick in turbidity downstream:

turbidity at the MacDonald Bridge gage on the Elwha River, 26-28 January 2014

Typically turbidity is closely linked to river flow, but in this case there was no increase in river flow - this turbidity was generated by the dam blast.

River discharge, MacDonald Bridge, 26-18 January 2014

A Tale of Two Decembers

An image stolen from Cliff Mass's blog post about Seattle's December 17, 2012 high water event

Do you remember last December? Likely you do, but perhaps not for the reason that I am thinking of. Last December (2012) was notable for the high water and coastal flooding that wet the shoreline of most of the Puget Sound region. That high water event was due to a convergence of really two factors - high astronomical tides (also known as "king" tides around these parts) and big "non-tidal residuals", or the component of water level that is not due to predictable tidal forces. Its worth noting that the non-tidal residual is really made up of a bunch of processes (that Cliff Mass describes here, I have described here, and others have described a bunch of places)...but for simplicity's sake I'm just going to treat collectively.

Water level data from Seattle from the December 17, 2012 high water event, which matched the previous record high water event from 1983. This plot includes the predicted water level (the blue line), the actual water level (the green line), and the difference between the two, which I term the "non-tidal residual" (the red line).

This December has been pretty mellow from a coastal flooding standpoint...so what is the difference? Last December the highest predicted tide during December in Seattle (as an example) was 3.91 m above MLLW, which is just about identical to this year's highest predicted high of 3.907 m above MLLW on Decmeber 6. Furthermore, the average predicted water level for December 2012 was 2.11 m above MLLW, while for 2013 it was the same. In other words, there is not a huge amount of difference in the astronomical tidal water level.

Seattle water levels for December 2012 (top) and December 2013 (bottom). The red line in each plot is the predicted water level, and the blue line is the actual water level.

The big difference between the two years was in the non-tidal residual, or the part of water level that is not predicted by the astronomical tide. In Puget Sound the non-tidal residual is most closely linked to atmospheric pressure, though it can also be due to other processes. Just a few days ago, for example, La Push, WA on the outer coast experienced large non-tidal residuals that were likely due primarily to wind piling water up against the coast.

The plots above, which show the predicted and actual water level from December 2012 and 2013 are sort of hard to interpret, so the plot below should help to clarify the different between the two months - this shows the difference between the predicted and actual water level for the two months:

So what should be clear is that in 2012 December water levels were much higher than those in December 2013, not due to "tides" (at least in the way that we usually think of them as being driven by astronomical forces), but rather due to very high average non-tidal residuals that lasted pretty much all month. In fact, the average of all measured water levels in December 2012 was 2.28 m above MLLW, while in December 2013 it was only 1.92 m above MLLW, a difference of over 14 inches. And when it comes to coastal flooding, 14 inches of water level makes a big difference...

In Memoriam: Maury Schwartz, Coastal Geologist

Dr. Maury Schwartz teaching a class...on the beach. Photographed by Hugh Shipman in 1991 or 1992

Dr. Maury Schwartz, eminent coastal geologist and Emeritus Faculty at Western Washington University, passed on a few days ago in Bellingham. When I started research work on the Elwha I was always distinctly aware of standing on Maury's broad intellectual shoulders; Maury spearheaded much of the early observational and descriptive work on Ediz Hook and the Elwha river delta, and also made significant contributions to the body of work that informs our conceptual models of the coastal geomorphological system at Elwha.

When I accepted a job with Washington Sea Grant in 2010 and started preparations for returning to Washington one of my fists tasks was to reach out to Maury via email. I was honored that he responded quickly and enthusiastically, and that initial email conversation led to an extended discussion via email and in person. As a relatively young entrant working in the field of coastal geology in Puget Sound, it was a huge honor to converse with Maury and trade ideas and debate the formation and evolution of our complex beaches, coastal spits and bluffs. I recall in particular meeting with Maury at a coffee shop in Bellingham, and leaving with a series of papers that Maury had brought for me along with a collection of napkins full of scribbles and notes on spit formation and development.

The last time I saw Maury was in the late summer of 2013, when Jim Johannessen brought Maury out to the Olympic Peninsula on what would be their final pilgrimage together to the beaches of the Elwha River delta. Jim and Maury had worked together in the 1990s and published one of the earliest, if not the earliest, comprehensive set of quantitative shoreline change analyses for the beaches adjacent to the Elwha River mouth. Maury was visibly weakened, but with our help was able to make his way across the logs and cobbles to lay eyes on the first of the sediment to reach the coast after the removal of the lower dam on the Elwha River. Maury's contributions to our understanding of the coastal landforms of Puget Sound were huge, and even during that final trip his passion for understanding their workings was clearly evident. To stand on the beach with him was an honor and an inspiration to try, in some small way, to continue his legacy.

Student research on Port Angeles Harbor

Students from my Introduction to Oceanography class deploy an oceanographic mooring off of the Port Angeles pier

My Peninsula College Introduction to Oceanography class just wrapped up for the quarter. This year, I tried a new thing (getting my students out on the water for a mini research cruise on the Olympic Coast National Marine Sanctuary's R/V Tatoosh), but also re-hashed an activity that was very successful last year: Building and deploying oceanographic moorings off of the Port Angeles pier. This year, though, I put more of an emphasis on analyzing the temperature and light data series that we collected between October and November.

The ingredients of a mooring

This is a tall order for students at the introductory level - I am asking them to create a hypothesis, plot these data and analyze them critically in order to try to ferret out patterns. But in the end I hope it is a valuable exercise and provides some insight into the process of science. Anyhow, I wanted to share one of this year's top papers, by Miranda Elsberry, who looked at the potential role that tides play in controlling the water temperature in the harbor. She does a nice job showing that in our data, there seems to be some relationship between the neap tide cycle and elevated water temperature in the harbo. Makes sense, right? We might assume that the residence time of water in the harbor goes up during the neap tide cycle, mixing is reduced, and temperature is thereby increased.

Introduction to Oceanography students building moorings

Anyhow,Here it is, in its entirety. Enjoy!

Tidal Water Levels and Bottom Water Temperature

For this final assignment I wanted to ask a question that I did not already know the answer to, I already knew the likely outcomes of questions like “Does Temperature vary with depth?” or “Does air temperature affect water temperature?” and so on. So I decided to explore the idea of tides. The question I had going into this assignment was: Does tidal water level affect the water temperature at the bottom of Station B? I chose to look at Station B because I thought that if the answer to my question was yes then it would be clearer at the medium depth of about 16 feet, rather than the deeper Station C or shallow station A. I did not choose to study Station A because of the possibility of the nearby creek changing the water temperature data.

Here are the stations referred to in her paper, for context

To see if there was a relation between water temperature and water level, I plotted the water temperature data collected by the Station B HOBO and the water level data that was provided in Canvas on the same chart. After plotting the data I looked for areas where the temperature and water level changed together.

Overall, I found that temperature did not clearly change with water level. However, even though the temperature line was clearly falling over time, there seemed to be a very slight change in the temperature plot where water level shows there was a neap tide cycle around the 16th and 28th of October. In my first plot (fig.1) I have circled the slight upwards bulges of the temperature line that occurred during the neap tide cycles.

Figure 1: Water Temperature at Bottom of Station B and Tidal Water Level Plot

I wondered if those slight changes were due to changes in air temperature instead of the tides. So I took the air temperature data that was provided in Canvas and plotted it on a chart with the bottom water temperature from Station B (fig. 2)

Figure 2: Air Temperature and Station B Bottom Water Temperature Plot

Other than the 5°F dip in air temperature and slight dip in bottom water temperature at the same time from around the 18th to the 23rd of October, the plot does not seem to show a very clear relationship between change in air and bottom water temperatures. So air temperature must not have caused the slight bulges in my first plot.

With plotting this data and examining it, I have found that there seems to be a connection between the water temperature at the bottom of Station B and the twice a month neap tide cycles. I do not know why neap tides would affect the temperature of water 16 feet below the surface, but there were very slight (by one degree) rise in temperature of the water when neap tides occurred. The change was very small, but it was visible on my chart, so it should be relevant. There are many other weather factors that I could explore that might have caused the temperature change, but air temperature did not seem to have caused it.